Q: is it correct to link against `libpython3.so` when building for stable ABI for android

[davidhewitt]

Downstream in PyO3 we are trying to get build configuration for the new Android distributions fully ironed out.

In particular we're looking at which shared library to link against when building for the stable ABI. We noted that the android distributions do include libpython3.so (without minor version) however we also noted the following text from PEP 738:

All Python extension modules must therefore be explicitly linked against libpython3.x.so when building for Android.

This wording specifically calls out the version-specific library. I cannot see technical reasons why we couldn't link against the stable ABI library instead, and the PEP doesn't appear to mention the stable ABI at all.

[mhsmith]

I wasn't thinking of the stable ABI when I wrote that sentence, but yes, it is correct to link against libpython3.so when building for abi3. However, this hasn't been well-tested on Android yet, so there may be bugs in tools such as cibuildwheel, or downstream distributions such as Chaquopy (chaquo/chaquopy#1380).

[davidhewitt]

Thanks, will proceed to link against libpython3.so in that case, and report back in separate issues if encountering any bugs!

[mhsmith]

It may also be necessary to remove -Wl,--no-undefined from the linker command line, since libpython3.so doesn't contain any symbols of its own and depends on them being brought in via DT_NEEDED.

[StanFromIreland]

If you have questions, if you could please post them in the Python Discourse Help category instead, thanks!